fix for MX25R1635F QSPI mode of operation #4460
Merged
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When the MX25R1635F flash IC is connected to nRF52840 over quad-SPI bus - the CircuitPython does not boot.
Primary reason for that is incorrect 'quad_enable_bit_mask' definition used in current 'devices.h'
This is an excerpt from the datasheet:
For compatibility reasons with all the family of the MX25R1635F IC's and with all the modes of operation it is worth to lower SPI clock frequency down to 8 MHz:
This PR fixes the issue - it is confirmed that MX25R1635F is doing good in QSPI mode afterwards.